It is common to wear a device around a wrist, the device, for example, being a watch, bracelet or wristband. Such a device typically includes a clasp. It may be difficult to fasten the clasp, especially for certain people.
People with poor dexterity may have difficulty fastening such a clasp. In particular, elderly people often have poor dexterity and so may have such difficulty. Some people also suffer a lack of feeling or numbness in their fingers, which can make fastening a clasp difficult. Such numbness is common in elderly people and this may exacerbate the difficulty caused by poor dexterity.
People suffering from certain mental conditions, such as dementia, may also have difficulty in remembering how to operate a clasp mechanism to fasten or undo the clasp.
People suffering from impaired eyesight may also have difficulty with certain known clasps; they may not be able to see small elements of the clasp.
Some existing attempts to address these problems have relied on making the clasp larger, since the elements are thus larger, easier to operate and easier to see. However, this disadvantageously results in larger, heavier and ugly clasps, which is particularly undesirable when the intended wearer of the device including the clasp may be a frail, elderly person.
Various clasps have been designed which include permanent magnets. For example, a known document, U.S. Pat. No. 2,648,884, discloses a magnetic clasp having two rigid, two-pole permanently magnetic parts with an interlocking tongue and groove connection to mechanically lock the two parts against relative sliding movement tending to separate the two parts.
Another known document, U.S. Pat. No. 4,941,236, discloses a strap for a wristwatch having a pair of separable flexible strap ends that can each overlap the other to provide an overlapped section. The strap ends nest against each other through mutually interlocking teeth, which prevents relative sliding movement of the two ends. The strap ends are also magnetised to impede unlocking of the teeth.
It is an object of the present invention to provide an improved clasp, which fastens together securely and can be undone easily.